Gas-electric apparatus



March 22, 1932-. w THORNE 1,850,734

GAS ELECTRIC APPARATUS Filed April 23. 1950 Patented `Mar. 22, V1932YUNITED STATES PATENT oFFicE WARD THORNE, F CHICAGO, ILLINOIS, ASSIGNORTO THORNE MOTOR CORPORATION,

OF CHICAGO, ILLINOIS, A CORPORATION OFJLLINOIS GAS-ELECTRIC APPARATUSApplication iiied April' 23,

' means to furnish electric power for driving a motor, though it may beused with generatoi-s connected to other types of loads.

This invention is illustrated as embodied in apparatus for driving avehicle in which the speed of the generator and the load thereon areboth frequently varied, with the result that the generator does notalways generate sufficient voltage to properly excite its own field. Theillustrated embodiment of this invention includes means for connecting abattery to increasethe strength of the field when necessary and at othertimes to reverse the connections of the battery so that the fieldcurrent will charge the battery without loss of ower.

ne object` of the invention is to provide means for more quicklyaccelerating gas-elec tric vehicles. To this end, means are provided formore quickly building up the generator by the use of an auxiliary fieldexciting current.

An additional object of the invention i s to provide means for charginga battery without loss of power. n

Another object of the invention is to provide means whereby abattery'can be used to excite a generator field and can thereafter becharged by the current flowing through the field coil.

A further object of the invention is to pro- Vide means whereby abattery connected in series with the generator iield can have itsconnections reversed Without permitting the generator to break down.

Other objects of the invention will appear from the followingdescription, drawingsand claims.

-In theA drawings, in which like numerals are used forv similar partsthroughout- Figure 1 illustrates diagrammatically one embodiment of theinvention; and

Figure 2 illustrates a slightly modified form of the invention in whichthe ballast resistance is not connected until just before ythe batteryconnections are reversed.

In Figure 1, one embodiment of the inven- 1930. Serial No. 446,508.

tion has been illustrated as including the motor 10, which according tothe usual practice is in driving relation with the wheels. The motor 10is driven by current supplied by the generator 12. The motor circuitincludes the wires 14 and416, suitable control means 18, Wire 20, motor10 including the usual connections, wire 22 and the wire 24, and back tothe generator armature, the wire 14 extending from the positive terminalof the generator 12. The generator 12 is driven by a gasoline engine orother power means and preferably is in direct engagement thedewith. Thegenerator l2 includes a field coil 26 which is preferably shunt wound.

One circuit for the field coil 26 is as follows: From the armature ofthe generator 12 through wire 24, through wire 28, through field coil26, through Wire 30, through ballast resistance 32, through wires 34 and36, through control resistance 38, which may be variable according tothe usual practice, and through wires 40, 42 and 14 back to the armatureof generator 12. Except for the use of the two resistances 32 and 38 inplace ofvone resistance, this circuit is similar to the customary shuntfield circuit.

With such a circuit alone, the generator is slow in building up as thefield is very weak at the start. To overcome this, it is customary toprovide some means for initially exciting the field. This inventioncontemplates a simple means of doing so with a small battery, such asused in ordinary lighting circuits, and of also charging said battery bythe field current after the generator has been sufficiently built up.For this purpose, relay 44 has been provided which is preferablyconnected by' wires 45 and 47 in parallelto the field coil 26 but may beconnected in series. When the motor and generator are idling,comparatively little current flows through the relay 44 and so itsarmatures 46 and 48 are in their lower positions, making connection withthe back contacts 50 and 52. The battery 54 is thus connected in serieswith field 26 and in such manner as to boost the current therethrough.

The boosting circuit is as follows From the positive side of the battery54 through wire 56, armature 48,back contact 50, wires 58, 60, 62, 64and 30, eld coil 26, wires 28 and 24 to the negative terminal of thearmature of generator 12, from the corresponding positive terminalthrough wires 14, 42 and 40, resistance 38, wires 36, 34 and 66, backcontact 52, armature 46, the wire connected therewith switch 70 and wire72 to the negative side of the battery 54. Thus the armature ofgenerator 12 and battery 54 work together to force the current throughthe generator field coil 26 to excite the generator field until thegenerator builds itself up to a suitable voltage. The constants of therelay 44 are such that when the generator reaches such voltage, whichmay be about thirty-six volts, the relay 44 becomes sufiicientlyenergized to raise the armatures 46 and 48. These armatures, togetherwith their connections, constitute a pole changing switch which reversesthe connections with the battery so that instead of,

boost-ing the flow of current through the field coil, the battery ischarged by that current.

The charging circuit is the same as the boosting circuit from thepositive side of the armature of the generator 12 to wire 66, but

' from there it extends through the other con- ,tact 74, throu h thearmature 48 and wire 56 to the positive side of battery 54, throuvh thebattery, through wire 72, switch 70, the

above connecting wire, armature 46,- front contact 76, wi'res 78, 62, 64and 30, and through the field coil back to the generator armature in theusual way.

To prevent the generator from breaking down when the armature isshifting from the back contacts to the front contacts, a

shunting ballast resistance 32 is connectedA between the wires 30 and34. This provides a lshunt across the battery.

' One characteristic of shunt-wound generators is that the voltage fallsoff as the ampere load gets larger. On an extremely heavy load, thevoltage gets so 1ow-that it cannot suiliciently'excite the field vrwiththe resultv that the generator breaks down. The present inventionovercomes this defect'by again `reversing the battery connections to boost the eld voltage before the voltage lowers to the criticalbreaking-down point. The constantsofthe relay 44 are such that when thevoltage across the field coil 26 drops for example to eighteen volts,the armatures n46 and 48 are dropped, again reversing the con nectionsto the battery 54.

The switch 7.0 may be provided in the battery circuit', to be openedautomatically when the engindand generator are idling so that there willnot be a waste of battery current.

The switch 80l may be provided to shunt the resistance 38 lif desired. ly

- The operation of the apparatus is as follows: To start the car, theengine is sped up, the switch i's' closed, closing tli'e boostingcircuit kof battery 54 to excite the'eld coil 26 and to increasethe-excitation thereof as the engine speeds up. Whenthe voltage reachesthe desired value, relay 44 is operlated to reverse the connections ofthe battery it is desired to reverse the connection of the battery. Thisis accomplished through the use of an additional relay 86. Thisrelay ispreferably a slow releasing relay and is connected across the field coil26. When the relay is suiiiciently energized, armature 88 is causedtocomplete the circuit through shunt resistance 32, and armature 90completes the circuit through relay 44 across the field coil 26. Sincethe relay 44 is not connected until the resistance 32is connected, therelay 44 ca'nnot be energized sufficiently to move the armatures 46 andV48 until after the shunt resistance 32 has been made effective toprevent breakin down of the generator.

' The constants o the two relays 44 and 86 should be such that thevoltage necessary to hold the armatures'of the relay 44 is at least ashigh as that necessary to hold the armatures of the relay 86. Shouldthere be a sudden drop in voltage across the generator field coil 26,the relay 44 will be deenergized at least as soon as the relay 86 ceasesto be externally energized, but as the relay 86 is of a slow releasingtype, it will retain its armatures until after the armatures 46 and 48of relay 44 have dropped to 'reverse the polarity changer so that thebattery 54 will boost the voltage in the field circuit.

Relay 86 may be given such constants as will cause it to pick up itsarmatures at a voltage considerably bel-ow that 'at which relay 44 picksup, and to drop them at as near as possible to the same voltage. Itwould be desirable to have the resistance yconnected whenever currentwould flow 32 would be connected when the generator had built itself upsufficiently to prevent a .serious drain on the battery through theshunt resistance. l The battery would then remain connected in boostingrelation until the generator, built itself ii'p fully to the voltage atwhich the connections would be reversed in. theapparatus of Figure 1. Asthe voltage of the generator drops, the polarity of the batteryconnections would again be reversed at abouteighteenfvolts, as in theapparatus of Figure 1, and the resistance 32 Would so remain connecteduntil the voltage across the field coil was so 10W as to fail t'o holdthe armatures of relay 86. This would preferably be before the currentfiow was such that the resistance 32 drained the battery uselessly. A

There areof course numerous other connections which may be made toaccomplish the desired results; for example, a device might be connectedin such relation with resistance 32 as to positively and directlyprevent current flowing through that resistance except in a directionwhich is useful in building up the field of the generator l2.

It is to be understood that many other embodiments of the invention,including some in improved form, will be apparent and in the course oftime will be devised by those skilled in the art. My invention includesall of these which come Within the spirit of the following claims,construed as broadly as the prior art will permit.

I claim:

l. The combination of-a generator includ- Y `is charged by the currentgenerated by said generator.

3. The combination of a generator including a shunt-Wound field coil, arelay connected across said coil, a polarity changing device controlledby said relay, a battery, said battery and field coil being soconnected4 to said polarity changing device that when the polaritychanging device is in one position, the battery boosts the flovv'ofcurrent through said field coil, and when said device is in anotherposition, the battery is charged by current flowing through said fieldcoil. 4. The combination of a generator including a shunt-Wound fieldcoil, a relay connected across said coil, a polarity changing devicecontrolled by said relay, a battery, said battery and field coil beingso connected to said polarity changing device thatwhen the polaritychanging device is in one position, the battery boosts the flow ofcurrent through said field coil, and when said deviceA is in anotherposition, the battery is charged by current flowing through said eldcoil, and-a resistance shunted across said polarity changer controlledby said relay, a battery, said battery and field coil being so connectedto said polarity changing device that when the polarity changing deviceis in one position, the battery boosts the fioW of current through saidfield coil, and when said device is in another position, the battery ischarged by current flowing through said field coil, and a shuntconnected across said polarity changer Wheneverl it is in neither ofsaid positions.

6. The combination of a generator including a shunt-Wound field coil, abattery connected in series with said field coil, and means forreversing the connections of said battery.

7 The combination of a generator including a shunt-Wound field coil, abattery connected in series with said field coil, means for reversingthe connections of said battery, and a resistance shunted across saidmeans While it is operating to reverse the connections.

8. A generator including a shunt-Wound field coil, a resistance and abattery each adapted to be connected in'series with said fieldv coil andto furnish separate paths for current to pass between a single point andsaid field coil, means for so connecting said resistance, and separatemeans for reversing the connections of said battery.

9. A generator including a shunt-Wound field coil, a resistance and abattery each adapted to be connected in series with said field coil andto furnish separate paths for current to pass between a single point andsaid field coil, means for so connecting said resistance, and separatemeans for reversing the connections of said battery, said last namedmeans being o erable only when the resistance is connected? l0. Thecombination of a generator including a shunt-wound field coil, a shuntand a battery each adapted to be connected in series with said fieldcoil,said shunt when connected being in parallel with said battery,means responsive to a certain voltage across said field coil forconnecting said shunt, and means for only thereafter reversing theconnections of said battery. i

l1. The combination of a enerator including a shunt-wound field coi ashunt and a battery each adapted to be connected in series with saidfield coil, said shunt when connected being in parallel with saidbattery,

means responsive toa certain voltage across said field coil forconnecting said shunt, and means responsive only thereafter to a voltageat least as high for reversing the connections of said battery.

A l2. The combination of a generator including a shunt-wound field coil,a battery, and means for connecting said battery in series with saidfield coil in boosting relation under certain conditions and in chargingrelation under other conditions said other conditions includingthepresence of a certain voltage across said field coil.

iso

13. The combination of a generator including a shunt-wound field coil, abattery, connections adapted to connect said battery in series with saidfield coil in both boosting relation and in charging relation, and meansresponsive to the generation of a certain voltage by said generator toshift said connections from one relation to tlie other.

14. The combination of a generator including a shunt-wound eld coil, abattery, connections adapted to connect said battery in series with saidfield coil in both boosting relation and in charging relation, meansresponsive to the generation of a certain voltage by said generator toshift said connec` tions from one relation to the other, a resistanteadapted to be connected in parallel with said battery and connections,and 'means tending to prevent the flow of current through saidresistance when the direction of iiow would be such as not to boost theexcitation of the ield.

15. The combination with a generator including a shunt-wound field coil,of a battery, polarity changing switch for selectively connecting thebattery in series with the field coil in charging relation and inboosting relation, and means responsive to the generation of a certainvoltage by said generator to operate the polarity changing switch.

16. The `combination with a generator including a shunt-wound fieldcoil, ofa battery, polarity changing switch for selectively connectingthe battery in series with the field coil in charging relation and inboosting relation, and means responsive to the same electricalinfiuences as is the field coil to operate the polarity changing switch.

4 17 The combination with a generator including a shunt-wound fieldcoil, of a battery, a polarity changing switch for selectivelyconnecting the battery in series in boosting and in charging relationwith the field coil, a resistance shunt across said switch, a relayshunted across the field coil and adapted to operate said switch at apredetermined voltage across the field coil.

v 18. The combination with a motor forl driving a vehicle and agenerator for supplying said motor with current, said generatorincluding a shunt-wound eldcoil, of a battery, a polarity chan 'ngswitch for selectively connecting the lattery in series in boosting andin charging relation with the field coil, a .resistance shunt acrosssaid shunt, and means for only thereafter reversingo the connections ofsaid battery. l

20. The'combination of a generator including a shunt-wound field coil, ashunt and a battery each adapted to be connected in Series with saidfield coil, said shunt when connected being in parallel with saidbattery, a slow release relay responsive to the gener- 'ation of acertain voltage by said generator for connecting said shunt, and meansfor only thereafter reversing the connections of said battery.

21. A generator having an excitation system including a shunt connectedfield exciting winding and a battery, and means including a currentcontrolling device for connectcomprising a battery, and a relayresponsive to the-voltage of said generator for connecting said batteryin series with the shunt eld exciting winding of said generator forroviding auxiliary excitation of said win ing' and for reversing thebatteryconnections in said field winding for causing charging of thebattery when the generator voltage reaches a predetermined value.

Signed at Chicago, Illinois, this 19th day of Apri1,' 1930.

WARD THORNE.

.for effecting rapid acceleration of the vehicle switch, a relayvshunted across the field coil" and adapted to operate said switch at apredetermined voltage across the field coil.

19. The combination of a generator including a shunt-wound field coil, ashunt and a battery each adapted to be connected in series with saidfield coil, said shunt when connected being in parallel with saidbattery, means responsive to the generation of a certain voltage by saidgenerator for. connecting said

